1From 28623c81b50663e946790649352cb1b3ed23954d Mon Sep 17 00:00:00 2001 2From: Max Filippov <jcmvbkbc@gmail.com> 3Date: Tue, 24 Sep 2019 04:15:17 -0700 4Subject: [PATCH] xtensa: fix PR target/91880 5 6Xtensa hwloop_optimize segfaults when zero overhead loop is about to be 7inserted as the first instruction of the function. 8Insert zero overhead loop instruction into new basic block before the 9loop when basic block that precedes the loop is empty. 10 112019-09-26 Max Filippov <jcmvbkbc@gmail.com> 12gcc/ 13 * config/xtensa/xtensa.c (hwloop_optimize): Insert zero overhead 14 loop instruction into new basic block before the loop when basic 15 block that precedes the loop is empty. 16 17Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> 18[Romain: rebase on gcc 8.4.0] 19Signed-off-by: Romain Naour <romain.naour@smile.fr> 20--- 21Backported from: r276166 22 23 gcc/config/xtensa/xtensa.c | 5 +++-- 24 1 file changed, 3 insertions(+), 2 deletions(-) 25 26diff --git a/gcc/config/xtensa/xtensa.c b/gcc/config/xtensa/xtensa.c 27index 08f9f7c7a8f..de206527810 100644 28--- a/gcc/config/xtensa/xtensa.c 29+++ b/gcc/config/xtensa/xtensa.c 30@@ -4232,7 +4232,9 @@ hwloop_optimize (hwloop_info loop) 31 32 seq = get_insns (); 33 34- if (!single_succ_p (entry_bb) || vec_safe_length (loop->incoming) > 1) 35+ entry_after = BB_END (entry_bb); 36+ if (!single_succ_p (entry_bb) || vec_safe_length (loop->incoming) > 1 37+ || !entry_after) 38 { 39 basic_block new_bb; 40 edge e; 41@@ -4253,7 +4255,6 @@ hwloop_optimize (hwloop_info loop) 42 } 43 else 44 { 45- entry_after = BB_END (entry_bb); 46 while (DEBUG_INSN_P (entry_after) 47 || (NOTE_P (entry_after) 48 && NOTE_KIND (entry_after) != NOTE_INSN_BASIC_BLOCK)) 49-- 502.24.1 51 52